Many consumer and industrial devices today use automatic transmissions filled with automatic transmission fluid (ATF) as the working fluid. At regular intervals, this automatic transmission fluid should be removed from the transmission and replaced with fresh fluid as the fluid properties degrade with time and use and entrain contaminants and debris which are not fully removed by the filter in the transmission.
When considering the typical personal automobile, the process usually involves removing the transmission pan from the transmission and allowing the fluid to drain therefrom. The pan is then reinstalled and new transmission fluid is added through the dipstick tube to bring the transmission to the proper fluid level. However, this process has a significant disadvantage. Specifically, the fluid that is present at a given time in the oil pan is only a small portion of the fluid actually in the transmission. Typically, a good deal of the transmission fluid remains in the control circuits of the transmission, the torque converter and the transmission cooler. Therefore, a traditional transmission fluid change will really only change about one-quarter to one-third of the transmission fluid and the transmission will be forced to operate with a mixture of old fluid and new fluid, thereby reducing its efficiency.
With commercial vehicles, such as trucks and the like, the same disadvantage also exists. Further, there is additional economic pressure to make the fluid change operation efficient and rapid. Any time the vehicle is out of service for a transmission change, the vehicle is losing money for the owner.
Therefore, a need exists for an improved concept in the changing of automatic transmission fluid which overcomes the disadvantage of replacing only a portion of the fluid and also performs this operation rapidly, efficiently and accurately to minimize cost and down time of the vehicle. The process and machine outlined herein is for all cooler cooled automatic transmissions, and most generally for those with radiator cooler systems. If the transmission is air cooled, the method herein outlined will not work, but there have been very few air cooled transmissions made, and fewer still left in operation.